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My Salisbury Disc swap and brake system customization

18737 Views 96 Replies 20 Participants Last post by  Spencedpete
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Long story short I wanted to go to Disc on my Sals and keep the drum length axles and wide spaced hubs. I ended up creating an entire new braking system using a mix of Rover and GM parts due to cost and performance issues.

Lets start with the drum to disc. I wanted to stick with solid rotors all around for parts commonality and cheapness

****if you use these instructions you WILL NEED to replace the master cylinder as it wont have enough volume to operate the rear 4 piston calipers*****

I ordered or purchased:

FRC6139 (used from Adam's old axle) This is a wide spaced front disc hub for a 90/110 from 1983-2006
Solid Rotors front x4
RTC5572 x2 RH front solid rotor caliper
RTC5573 x2 LH front solid rotor caliper
Sfp000260 x2 Pads set for above calipers
Rtc5001 x2 retaining pin set for calipers
RTC3511G x2 Twin lip hub seals
FRC3988 x4 drive flange gaskets
Timken SET37 wheel bearings x4 from amazon
Stick of Lucas X-tra heavy duty green grease from walmart
and
Red winches 4 piston caliper bracket for rear axles
Rear Axle Disc Brake Conversion - Landrover Defender
Russle speed bleeders 639630 m10x1x33
Russell 639630: Speed Bleeders 10mm x 1.0 | JEGS


****the red winches bracket is made for Rover stle rear axle but will work with modification for Sals (important later)****


Steps:

Install speed bleeders into all calipers
Remove rear wheels and place truck on axle stands
Remove drive flange bolts and axle circlip
Remove drive flange and slide out axle
Remove drum retaning screw (may have to be drilled out)
Slack both adjusters on the backing plate with 13mm deep 6 point socket
Remove drum ( may need to be hammered off)
Loosen 11mm brake line fitting but leave in place on wheel cylinder
Bend back lock plate on the outer hub nut
Remove outer hub nut
remove lock plate
Remove inner hub nut
Yank entire hub assembly and put aside
Remove the six 17mm head bolts and nuts around the center of the stub axle (nut on the outside face of the axle flange)
Now remove brake line from the wheel cylinder and cap it with a rubber plug to avoid a mess
Tap or yank off backing plate
Keep the round bolt head spacer part # FRC3147
Put the fresh races and newly greased bearings into your FRC6139 front disc hubs and install the rear hub seal as deep as it will go, lips facing out
Install the new rotors onto the hubs with fresh lock washers or red locktite (or both)
Cleanup the stub axle with some red scotchbrite pad then brake or carb cleaner
Lightly grease the stub axle to aid assembly
Pack grease into the lips of the rear hub seal
Cut FRC3147 (spacer we kept from the dum setup) into two pieces so you have two equal sizes spacers with three bolt holes each, stack these together.
We will use these spacers to mount the Red winches bracket
With three fresh long bolts and nuts from the Red winches hardware kit mount the bracket on the 2o'clock position on the axle
Use the thick and thin washers from the kit to align with the hub and rotor combo
Slide hub and rotor onto the stub axle (may need to wacked with a piece of wood or a deadblow as the new bearings are a tight fit)
Install one of the hubnuts enough to keep it in place
Install one of the calipers with the included hardware from the red winches hardware kit
Eyeball that the caliper is square to the rotor and centered over the rotor, if not remove or add washers to the red winches bracket and cut up spacers
(My truck only needed one thin washer on each bolt for the caliper to be dead center)
Now remove the hub, rotor, caliper
Install the rest of the bolts and tourque to spec adding loctite
Reinstall the hub, rotors, caliper, ect
Install hutnut, locking plate (replace if it is really jacked up) and outer hub nut
Install axle shaft
Install drive member and circlip

Sit back and relax you are 1/2way there !

****TAKE NOTE on the short side of the axle you will need to notch the lower shock mount by 3/8 of an inch to allow the bracket and caliper to fit***


You have a decision to make now. you can leave the stock hardlines in place or replace them with flexlines and banjo bolts. I opted to move to flex lines as the hard lines are very close to the coils and the banjo will fit tighter and be more resistant to abrasion, AND it makes bleeding the nearly horizontal calipers much easier.


For my rear flex lines I used parts from pegasus racing:

1x 3-18-S-B 18in an3 flex line with swivel fitting one side and banjo on the other
1x 3-40-s-b 40in an3 flex line with swivel fitting one side and banjo on the other
4x 3241-3/8 soft copper 10mm or 3/8 crush washer
2x 3242-003 banjo bolt 10mmx1 short
2x 3265-16 male 10mmx1 convex to an3 male adapter


Frankly I measured the lines two times and the are still a little short so you can add 3-4in to the line lengths to give yourself more room.

The banjos will need to be shortened by about 5mm to avoid bottoming out in the caliper, i used a cutting disc to do this

Put the metric to an adpaters in the "T" mounted on your axle diff cover
Install the shortened banjos with crush washers finger tight
Route flex line to the "T" and tourque
Now tourque the banjo bolts


OK 75% of the way there !

***From this point on im going to assume you know how to identify and create brake line nuts/flares/ect***

I wanted to reaplace the absolute garbage LR booster options and the garbage masters. After some research I found that a universal style 3 and 3/8 square pattern hot rod/chevy style brake booster will fit the Defender pedal box with minimal mods.

I settled on a 11in dual diaghpram brake booster as its was the largest I could find and that would fit my RHD truck, LHD may be different.
I also decided on a Corvette syle 1 1/8 in dual circut master. These are widely avialable but, make sure to get one rated for disc/disc applicaitons. Disc/Drumn versions will have a 10lb residual valve built into the rear circut that will cause the rear discs brakes to drag.

Booster
100% Brand New Universal 11 Dual Diaphragm Zinc Brake Booster Hot Rod Street | eBay
Master:
Tuff Stuff Performance #2071NB - TUFF STUFF Performance Accessories
You can also just buy a combo unit with a Dual 8in or dual 9in booster. All will fit and work, when i first built this i used a dual 8in to conserve space (that i didnt need to) and it worked 95% as well as the dual 11in
For example:
Tuff Stuff Performance #2124NB - TUFF STUFF Performance Accessories
I also added a wilwood 2lb residial valve to the rear circut only. I assumed that the nearly horizontal rear caliper mounting may cause issues with fluid runback. This wasnt the case but it cant hurt.
https://www.summitracing.com/parts/wil-260-13783/overview/
And to top it all off I used a SSBC single circut bias valve to control the flow of fluid to the rear brakes. Since the massive calipers have insane stopping power,if the truck is unloaded or not towing they can lockup to easily, this allows for adjustment of the rear circut bias(power).
Buy Universal Aluminum Adjustable Proportioning Valve for Rear Brake Bias at SSBC


The Steps for install:

Remove round covers from the side of the pedal box
Remove cotter pin from pedal arm pin
Push pin out and let fall to the floor of the truck
Collect up the pin, cotter and the heavy washers, put aside
Remove brake lines going into the stock master, note the position
remove 17mm nuts holding stock master to booster
remove stock master
remove 4 nuts holding stock booster to pedal box
remove vac hose from booster
remove booster
Measure the height of the pedal rod clevis ont the stock booster and note it
Using cutting disc cut off the clevis from the stock booster flush with the rear of the clevis
Discard stock booster
Place clevis in a vise and centerpunch the rear of the clevis
Drill with 21/64 or similar size
Tap clevis for 3/8-24 (fine thread)
INstall tapped clevis to aftermarket booster and check for height
Aftermarket booster rod will have to be trimmed aby about 5mm height to allow for pedal assembly and pin to line up
Remove clevis, mark and trim rod
INstall 3/8-24 jam nut then clevis with blue locktite
MEasure height then tourque into place
Aftermarket booster is now ready to mount
Looking that the defender pedal box you will see that the inner unused bolt holes are reeeeealy close to the bolt pattern of the aftermarket booster.
Using a unibit open up the holes and test fit the booster until good to go.
Install aftermarket booster onto defender pedalbox with opened up holes
Install pedal arm pin, washers and cotter pin after greasing them up.
Using a grease pencil or girlfriends nailpolish mark the end of the boosters actuator rod (part that pokes into the master)
Slide new master onto the booster then check that your booster and master are mating correctly, you should now have paint or grease on both the actuator rod and the master
If you do not have markings on both sides adjust the actuator as needed (some are threaded some need shims)
Create your required brake lines and fittings
I plumbed a 2lb resudial valve into the rear circut, this is optional
I also plubmed the SSBC brake bias valve ****AFTER**** the LR PWDA valve mounted on the bulkhead (see pics)
You plumb this after to avoid the PWDA from indicating a pressure issue on the rear circut.
IF you havent already rebuilt your PWDA now is a good time to (see my other post on this subject) or remove it, your choice
http://www.defendersource.com/forum/f6/fyi-pwda-valve-116281.html
Bench bleed your new master then install into the booster
If you have the old style coolant overflow tank it may need to be moved over an inch or so, or just temporarly removed to install the master.
Now hook up you new lines and bleed your brakes!



DONE !!!!!!


Phew that was alot to type. post or PM with questions

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Thanks for the write up! Just found a leaky brake line so, well, here we go again!
Good luck !
I just "completed" the brake booster upgrade. I say completed in quotes because my brakes don't work. Pedal compresses but the brake pressure is abysmal--as in barely enough pressure to stop the car. So I am working on that--no clue which component isn't don't its job...yet...

But this post is to update folks on the pedal box/booster attachment. I was under the impression that the pedal boxes were all the same, but I can verify that at least the 1994 NAS has a very different drill pattern for the booster than does the ROW. The bolts are not even close to the same places. I fortunately had a ROW pedal box (and my wife calls me a pack rat that just can't throw any part out... Thank goodness though!!) so I relaxed those holes and installed the whole assembly.
But this post is to update folks on the pedal box/booster attachment. I was under the impression that the pedal boxes were all the same, but I can verify that at least the 1994 NAS has a very different drill pattern for the booster than does the ROW. The bolts are not even close to the same places. I fortunately had a ROW pedal box (and my wife calls me a pack rat that just can't throw any part out... Thank goodness though!!) so I relaxed those holes and installed the whole assembly.
The pedal box and booster changed from early to late. NAS and ROW are the same.
Bummer well let's try and figure out what went wrong. There are a ton of variables but early call outs would be :

What type of master/booster ?

Did you bench bleed the new master ?

Does your new master have a pushrod adapter for powerbrakes or a hole for nonpower applications?

If you have the adapter in place , does the booster pushrod *just* touch the master adapter when installed ? Nail polish works well for this test. Adjustment can be made at the booster side on most Chevy style boosters .

Bled the system , including g valve if present , starting with the furthest component?

If you removed the rear drums did you adjust the rear brakes until the slightly dragged then backed it off a few clicks ?

If you removed the rear shoes , did you assemble them in the correct orientation ? They look super similar, leading and trailing.

Vac line hooked up to the booster ?

I like to use speedbleeders for a good bleed .


I just "completed" the brake booster upgrade. I say completed in quotes because my brakes don't work. Pedal compresses but the brake pressure is abysmal--as in barely enough pressure to stop the car. So I am working on that--no clue which component isn't don't its job...yet...

But this post is to update folks on the pedal box/booster attachment. I was under the impression that the pedal boxes were all the same, but I can verify that at least the 1994 NAS has a very different drill pattern for the booster than does the ROW. The bolts are not even close to the same places. I fortunately had a ROW pedal box (and my wife calls me a pack rat that just can't throw any part out... Thank goodness though!!) so I relaxed those holes and installed the whole assembly.
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This is on my NAS, so I am starting with disc brakes all around.

I am using the dual diaphragm 11" ebay booster: https://www.ebay.com/itm/100-Brand-...rentrq:c7c91e0416b0a9cb6bf029dfff863368|iid:1
The Tuff Stuff 2071NB master:https://www.tuffstuffperformance.co...-rods-customs-muscle-cars-as-cast-2071nb.html
The Summit Racing Proportioning Valve: https://www.summitracing.com/oh/parts/sum-g3906/overview/?rrec=true
I am using new Speed Bleeders on all 4 corners (which I LOVE!)

I bench bleed the brake master before putting it in. I also bench bled it in the truck a second time after the brakes did not work.

I have bled more fluid through the system than Keith Richards on a bender.

I have the adapter in the Tuff Stuff that came in it. It has a pointy end and a cup end. The cup end is out. I put some prussian blue on the end of the cup and it comes off on the master cylidner plunger. (this particular master cylinder doesn't have an adjustable plunger--but I can take out the assembly and it appears I can put shims in behind it to adjust it). I don't believe I need to adjust it but...

The proportioning valve is mounted on top of the master cylinder (so before the PRV/bias valve)--it is mounted horizontally, but I believe that is fine based on knowledge of it's function and no indication by any manufacturer on orientation specificity...

When I press down on the brake pedal, I get a "whoosh" sound (which the Chevy folks say is normal as this is sucking air into the booster) but I get a fair amount of free travel before anything is really happening. THis to me says that the booster is not adjusted correctly, but if I put in a longer plunger rod, and try and put the cylinder on, it pushes in on the master cylinder which is a big no-no. So for now, let us say that the combo is in agreement.

The brake pedal does seem to slowly bleed out to the floor and it is only the later 1/2 that seems to have any pressure. With the cap off the master only seems to have a "fountain" out of the front most reservoir (furthest from the bulkhead) which to me says that I am not getting anything out of the first plunger in the master--which could account for the extended travel of the pedal. BUT when bleeding the brakes, I get strong fluid transfer out the calipers. When I bled the brakes I started at the furthest rear corner. Proportioning valve opened to full. Strong fluid flow out of all 4 corners, first with air, then completely air free. Loads of fluid.

Checked the engine vacuum and I am getting about 18 inHg

I am going to remove the master and bench bleed it again. I don't have another choice. I will check the booster while I am at it, but i don't know what there to really check or how to check it with the master off--but I will look.

I can barely stop the truck when the brake on--if the engine surged, I would roll. It is that weak. Even if the booster was shot, I would expect the manual actuation of the brake to be sufficient but it is not even close to that. Not leaking anywhere. The PRV (bias valve) is still in place-- everything is suspect until I get things solved. I have adjusted my bias valve to full open and closed just in case it was causing that to trigger, but even triggered it would not reduce the pressure to all 4 corners of the vehicle just the front or the rear.

So I am off to the driveway and remove the master...again... and take a close look at it and bench bleed it for the 3rd time but not expecting any miracles, just more mild frustration... Plus it is 90F in the sun which is getting me pretty tan (or burned...).
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Looks like you have your bases covered. I'd suspect bad master at this point. You can go to any parts store and get a new master for a 68 Corvette. Should be around $50 , swap and test . Fittings should be the same
Hey Davis, you’ve described almost exactly what I went through a couple of months ago with a brand new disc/drum setup and all new brake lines. I used basically the same MC and booster from Tuff Stuff, I rebuilt the PDW valve, rear brake shoes positioned properly, bench bled the master three times and and using various methods bled through a gallon and a half of fluid, no joy, low brake pedal. What finally worked for me was to use my pressure bleeder at each wheel to push the fluid up to the master and finally got a high pedal. I did try the speed bleeders, as they seemed appealing, but I had to torque the loving crap out of them so they wouldn’t leak, replaced them with the standard fittings.
Well I just re-bench bled the master. It is back together but I have to go get fluid, lol. Off to the parts store...again... I'll report back after I bled the **** out of these brakes... If not, then I will try a different master...
4
The pedal box and booster changed from early to late. NAS and ROW are the same.
Which means that Naplm must have used an early style in his write up--good to know. If you are using a late style, you will need to redrill all the holes or use an early style and relax the holes a bit.

Everything is back and bled and it is getting there. More than 80%. What I love is now I can feel the booster and in a lot of braking scenarios it is awesome. But if I am pumping the brakes, after 2 or 3 pumps, the "boost" has packed up/run out and I get manual braking which isn't where it needs to be. There are going to be a lot of times off road particularly downhill when I will be repeatedly pressing the brake easing the truck and trailer over obstacles. So I need to figure out that. But really close. Do any of you have an issue with boost not being present unless it gets a "recharge"? My idle vacuum is decent, not amazing, but I still expect a little to be in reserve. Guess not. I have check the check valve and it seems to be operating. If all else fails, I will add a vacuum boost can/check valve to store up residual vacuum but I don't thinK I should have to.

Anyone else pump the brakes and get an absence of boost with "substandard" brakes at that point?

So doing much better, but not quite there yet. Good to drive. I have some more bleeding tricks--but I am done right now. I have done more bleeding than an Ebola outbreak. (still too soon? argh)

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"Anyone else pump the brakes and get an absence of boost with "substandard" brakes at that point?"
Yes. I've not had time to troubleshoot as my rig is disemboweled for a rewire; I have good vacuum as well, so I'm at a loss as to what it could be. Keep us posted. Thanks!
I'm not sure if I put it in the write up or not but I run a 10 lb inline residual valve for the rears. Yes I know what 10 lb valve is designed for drum brakes but it seems to work great in my truck. Keeps the pads nearly touching the rotors and reduces pedal travel.

Maybe you guys can shim your front and rear brakes to see if that's the issue?
Checked the engine vacuum and I am getting about 18 inHg.




This was not enough for my truck, Most of these "chevy " style boosters require 22 for a good pedel feel . I had 18 and it felt like manual brakes. I added a vacume booster pump and got 22, now it works great feel like a modern car.
Checked the engine vacuum and I am getting about 18 inHg.




This was not enough for my truck, Most of these "chevy " style boosters require 22 for a good pedel feel . I had 18 and it felt like manual brakes. I added a vacume booster pump and got 22, now it works great feel like a modern car.
I’m at 17inHG at idle. Spikes higher but settles there. I’ll look into those pumps— what version did you get? Electric or engine-driven?
After reviewing my brakes, power and set up, I believe I’m just running short of vacuum volume capacity and not vacuum intensity, so the simple/inexpensive way for a larger dual diagram is just increasing capacity with a vacuum canister. I’ll try that first.
electric from flebay



search for
Electric Vacuum Pump Power Brake Booster Auxiliary Pump
I had no idea the Rover V8 had so little vac . The Chevy booster needs a minimum of 15 to work

You don't need an electric pump , you may need a canister
I have done everything to this brake system, bench bled 4 times, forward and reverse bled, speed bleeder bled, everything. Not the braking I'd expect. I am now 99% it is the brake master cylinder.

When bench bleeding the Tuff Stuff 2071NB, it also only has fluid going through the front bleed hose for the first 1/3 of the pump and then front and rear. this is also triggering the pressure reducing valve on my bulkhead (NTC8836) also complicated things (I can hear it activating/clicking).

Brakes are not difficult systems and it is not my first rodeo, but this one has definitely got my number on frustration. Gonna just pick up a new master...
Hydroboost.
Hydroboost.
Always an option, just shouldn’t be necessary in this case. May consider it for the om606 swap though...
Can you post a pic of your bulkhead valve ?
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